Buggy code:
public class CompletionJavadocParser extends JavadocParser { public static final int INLINE_ALL_TAGS_LENGTH ; public static final int BLOCK_ALL_TAGS_LENGTH ; char [ ] [ ] [ ] levelTags = new char [ 2 ] [ ] [ ] ; int [ ] levelTagsLength = new int [ 2 ] ; int cursorLocation ; CompletionOnJavadoc completionNode = null ; boolean pushText = false ; public CompletionJavadocParser ( CompletionParser sourceParser ) { } public boolean checkDeprecation ( int commentPtr ) { } protected boolean commentParse ( ) { } protected Object createArgumentReference ( char [ ] name , int dim , boolean isVarargs , Object typeRef , long [ ] dimPositions , long argNamePos ) throws InvalidInputException { } protected Object createFieldReference ( Object receiver ) throws InvalidInputException { } protected Object createMethodReference ( Object receiver , List arguments ) throws InvalidInputException { } protected Object createTypeReference ( int primitiveToken ) { } private char [ ] [ ] [ ] possibleTags ( char [ ] prefix , boolean newLine ) { } private CompletionJavadoc getCompletionJavadoc ( ) { } private CompletionParser getCompletionParser ( ) { } private void initLevelTags ( ) { } protected Object parseArguments ( Object receiver ) throws InvalidInputException { } protected boolean parseParam ( ) throws InvalidInputException { } protected boolean parseReference ( ) throws InvalidInputException { } protected boolean parseTag ( int previousPosition ) throws InvalidInputException { int startPosition = ( this . inlineTagStarted ) ? this . inlineTagStart : previousPosition ; boolean newLine = ! ( this . lineStarted ) ; boolean valid = super . parseTag ( previousPosition ) ; boolean inCompletion = ( ( ( this . tagSourceStart ) <= ( ( this . cursorLocation ) + 1 ) ) && ( ( this . cursorLocation ) <= ( this . tagSourceEnd ) ) ) || ( ( ( this . tagSourceStart ) == ( ( this . tagSourceEnd ) + 1 ) ) && ( ( this . tagSourceEnd ) == ( this . cursorLocation ) ) ) ; if ( inCompletion ) { int end = this . tagSourceEnd ; if ( ( this . inlineTagStarted ) && ( ( this . scanner . currentCharacter ) == '}' ) ) { end = this . scanner . currentPosition ; } long position = ( ( ( long ) ( startPosition ) ) << 32 ) + end ; <START_BUG> int length = ( ( this . tagSourceEnd ) - ( this . tagSourceStart ) ) + 1 ; <END_BUG> char [ ] tag = new char [ length ] ; System . arraycopy ( this . source , this . tagSourceStart , tag , 0 , length ) ; char [ ] [ ] [ ] tags = possibleTags ( tag , newLine ) ; if ( tags != null ) { this . completionNode = new CompletionOnJavadocTag ( tag , position , startPosition , end , tags ) ; } } return valid ; } protected boolean parseThrows ( ) { } protected boolean pushParamName ( boolean isTypeParam ) { } protected void pushText ( int start , int end ) { } protected Object syntaxRecoverQualifiedName ( ) throws InvalidInputException { } protected Object syntaxRecoverArgumentType ( Object receiver , List arguments , Object argument ) throws InvalidInputException { } protected Object syntaxRecoverEmptyArgumentType ( Object methodRef ) throws InvalidInputException { } protected void updateDocComment ( ) { } }

Fix:
int length = ( ( this . cursorLocation ) + 1 ) - ( tagSourceStart ) ;